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The Gol‐e‐Zard Zn‐Pb Deposit, Lorestan Province, Iran: a Metamorphosed SEDEX Deposit
Author(s) -
ZARASVANDI Alireza,
SAMETI Mona,
SADEGHI Martiya,
RASTMANESH Fatemeh,
POURKASEB Hooshang
Publication year - 2014
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12188
Subject(s) - sphalerite , geochemistry , galena , geology , mineralization (soil science) , hydrothermal circulation , gangue , chalcopyrite , calcite , mineralogy , pyrite , chemistry , copper , organic chemistry , seismology , soil science , soil water
The Gol‐e‐Zard Zn‐Pb deposit is one of several sediment‐hosted Zn‐Pb deposits found in the central part of the Sanadaj‐Sirjan Zone, known as the Isfahan‐Malayer belt, western Iran. Mineralization occurs in Upper Triassic to Jurassic phyllites and meta‐sandstones. Sphalerite and galena are the most abundant metallic ores, with minor chalcopyrite. Calcite and quartz are the main gangue minerals. Fissure filling, replacement textures and especially mineralized faults, suggest an epigenetic stage in the Gol‐e‐Zard deposit formation. Geochemical studies of mineralized rocks show high concentrations of Zn, Pb and Cu, (Zn and Pb > 10000 ppm and Cu average 3000 ppm). LREE enrichment (LREE>HREE, La/Lu average 1.44) and positive Eu anomalies (Eu/Eu*>1 average 1.67) indicate reducing conditions during the deposition of deposit. However, some samples do not display negative Ce anomalies, which indicate that localized oxidizing conditions are also present. This study indicates that the Gol‐e‐Zard deposit formed due to circulating hydrothermal fluids in a marine environment. A SEDEX‐type genesis, which is defined by circulating hydrothermal fluids through sediments in a marine environment, and syngenetic precipitation of Zn and Pb sulphides, is suggested for the Gol‐e‐Zard deposit. Emplacement of some granitoid intrusions such as the Aligudarz granitoid intrusion remobilized mineralizing fluids and metamorphosed the Gol‐e‐Zard deposit.